The purpose of this study is to assess the effect of canagliflozin (JNJ-28431754) compared to placebo in the treatment of participants with Type 2 Diabetes Mellitus (T2DM), who have inadequate glycemic control on maximally or near-maximally effective doses of metformin and sitagliptin.

This is a randomized (the study medication is assigned by chance), double-blind (neither physician nor participant knows the identity of the assigned treatment), placebo-controlled (an inactive substance that is compared with a study drug, to test whether the study drug has a real effect), multicenter study of efficacy, safety, and tolerability of canagliflozin in participants with T2DM, who have inadequate glycemic (blood sugar) control on maximally or near-maximally effective doses of metformin >=1500 mg/day and sitagliptin 100 mg/day. Approximately 200 participants will be randomly assigned to 1 of 2 treatment groups in 1:1 ratio for 26 weeks. During the study the participants will be also provided with diet and exercise counseling (standardized non-pharmacological therapy).

Inclusion Criteria:

• Must have a diagnosis of type 2 diabetes mellitus
• Must have a screening HbA1c of >=7.5% to <=10.5%
• Must be on metformin >=1500 mg/day and sitagliptin 100 mg/day (or equivalent fixed dose combination) at a stable dose for at least 12 weeks before screening

Exclusion Criteria:

• History of diabetic ketoacidosis or T1DM, hereditary glucose-galactose malabsorption or primary renal glycosuria
• A myocardial infarction, unstable angina, revascularization procedure or cerebrovascular accident within 12 weeks before screening
• eGFR <60 ml/min/1.73m2, or serum creatinine >=1.4 mg/dL for men and >=1.3 mg/dL for women
• Known significant liver disease (eg, acute hepatitis, chronic active hepatitis, cirrhosis)
• Major surgery (ie, requiring general anesthesia) within 12 weeks before screening